ROWING WORLD CUP III Venue: Lucerne, Switzerland Dates: 10-12 July Coverage: Live on the red button and BBC Sport website (UK only) on Sunday, with highlights on BBC Two on Monday, 1300-1400
Grainger was back in form after having a tough time in Munich
Sculler Katherine Grainger and the men's pair of Andy Hodge and Pete Reed were among seven British heat-winners at the World Cup regatta in Lucerne.
But the women's double scull missed out after Olympic silver medallist Annabel Vernon was forced out through illness.
Anna Bebington and substitute Ro Bradbury must now use Saturday's repechage to try to reach the last six.
Ten British crews progressed from the heats, with four straight into finals and six in semi-finals on Saturday.
Grainger's performance was particularly pleasing after her disappointment in Munich three weeks ago, when she finished out of the medals.
"I've done a lot of technical work since Munich and we put it to the test today," said the Scot.
"As this is the biggest field yet at a World Cup in my event I thought today would be a bit unpredictable but I'm pleased with the result."
Reed and Hodge were five seconds slower than New Zealand duo Eric Murray and Hamish Bond, who raced in the other heat and have beaten the British pair in their last two events - in Munich and Henley.
Speaking before racing, Reed admitted: "I've got to say very honestly that they're faster than us at the moment.
"Our aim is to be a lot closer to them and put the rest of the world behind us.
"If it's two boats racing for the line, 10 seconds ahead of the rest of the field, that's going to be ideal for us."
Double scullers Matt Wells and Stephen Rowbotham finished behind France after leading early but qualified for the semi-finals.
"They had a good start to their race but now we've got a difficult task ahead," said their coach Mark Earnshaw.
"New Zealand and Germany and France are all strong here."
Sophie Hosking and Hester Goodsell, winners of GB's first ever lightweight World Cup gold in Munich, won their heat from Greece to move into the semi-finals.
The women's pair of Olivia Whitlam and Louisa Reeve, the men's four, lightweight men's and women's doubles and lightweight sculler Adam Freeman-Pask also won heats.
The GB men's quad reached the final despite finishing behind Germany in their heat but a new-look men's eight were third and now face a repechage.